Molecular and Genetic Medicine

Study of a Colombian Family with Hypertrophic Cardiomyopathy and Sudden Cardiac Death Associated with the Lys247arg Mutation in the Cardiac Troponin T (Tnnt2) Gene: Casual Relationship or Polymorphism?

Abstract

Guillermo Mora Pabón, Juan Fernando Agudelo, Diego Alberto Molina, Maria Fernanda Garcés, Jorge Eduardo Caminos, Karen Orjuela, Catarina Allegue, Rocio Gil, Angel Carracedo and Maria Brion

Introduction and Objectives: Hypertrophic cardiomyopathy is the most common genetic cardiovascular disease. Mutations have been described in at least 27 genes that can encode sarcomere proteins, mitochondrial proteins and proteins that control calcium handling. This report shows a family with Hypertrophic cardiomyopathy in the presence of sudden death. Methods: We performed a clinical, genetic and molecular biology to establish the phenotypic and genotypic commitment of this disease. We analyzed a total of 592 mutations in 16 genes spread ACTC, GLA, MYBPC3, MYH6, MYH7, MYL2, MYL3, MYLK2, MYO6, PRKAG2, TCAP, TNN1, TNNI3, TNN2, TPM1 and TTN. Results: We determined phenotypic and genotypic characteristics of 37 members belonging to one family in five generations. Lys247Arg (K247R) mutation was found in 13 family members (38.23%) of which 3 had hypertrophy on echocardiography, but two patients had hypertrophy and they did not have the mutation. Moreover, a patient carries the mutation but the mother does not. The father (not related to the family) carries this mutation. Conclusions: We present a Colombian family with hypertrophic cardiomyopathy and sudden death where described causal mutations in the sarcomeric genes were evaluated. K247R genetic variant in the Troponin T type 2 gene was found with no correspondence to the phenotypic expresion of the disease in the family.